general protection fault in tcf_ife_init

[syzbot <syzbot+fbb5b288c9cb6a2eeac4@syzkaller.appspotmail.com>]

Hello,

syzbot found the following crash on:

HEAD commit:    3bfe1fc4 Merge tag 'for-5.3/dm-changes-2' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=163c6e58600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f8841b9f4365c7de
dashboard link: https://syzkaller.appspot.com/bug?extid=fbb5b288c9cb6a2eeac4
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=110322afa00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12c1c168600000

The bug was bisected to:

commit 2de50e9674fc4ca3c6174b04477f69eb26b4ee31
Author: Russell Currey <ruscur@russell.cc>
Date:   Mon Feb 8 04:08:20 2016 +0000

     powerpc/powernv: Remove support for p5ioc2

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10367478600000
final crash:    https://syzkaller.appspot.com/x/report.txt?x=12367478600000
console output: https://syzkaller.appspot.com/x/log.txt?x=14367478600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+fbb5b288c9cb6a2eeac4@syzkaller.appspotmail.com
Fixes: 2de50e9674fc ("powerpc/powernv: Remove support for p5ioc2")

netlink: 4 bytes leftover after parsing attributes in process  
`syz-executor960'.
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9229 Comm: syz-executor960 Not tainted 5.2.0+ #69
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:nla_parse_nested_deprecated /./include/net/netlink.h:1167 [inline]
RIP: 0010:tcf_ife_init+0x25c/0x1850 /net/sched/act_ife.c:484
Code: 00 00 48 c7 c7 40 c2 da 88 e8 f0 8c a2 fb 48 89 da 48 b8 00 00 00 00  
00 fc ff df 48 c7 85 e8 fe ff ff 00 00 00 00 48 c1 ea 03 <0f> b6 14 02 48  
89 d8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 e2
RSP: 0018:ffff88809032eeb8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff110119c21b0
RDX: 0000000000000000 RSI: 1ffff110119c21b7 RDI: 0000000000000282
RBP: ffff88809032f060 R08: 0000000000000002 R09: ffff88808ce10d88
R10: fffffbfff134a0cf R11: ffffffff89a5067f R12: 0000000000000001
R13: ffff8882166dd240 R14: ffff88809032f8c0 R15: 0000000000000000
FS:  0000555556e20880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000180 CR3: 0000000088374000 CR4: 00000000001406f0
Call Trace:
  tcf_action_init_1+0x6f2/0xa80 /net/sched/act_api.c:915
  tcf_action_init+0x241/0x360 /net/sched/act_api.c:971
  tcf_action_add+0xe8/0x370 /net/sched/act_api.c:1356
  tc_ctl_action+0x3b5/0x4bc /net/sched/act_api.c:1408
  rtnetlink_rcv_msg+0x463/0xb00 /net/core/rtnetlink.c:5223
  netlink_rcv_skb+0x177/0x450 /net/netlink/af_netlink.c:2477
  rtnetlink_rcv+0x1d/0x30 /net/core/rtnetlink.c:5241
  netlink_unicast_kernel /net/netlink/af_netlink.c:1302 [inline]
  netlink_unicast+0x531/0x710 /net/netlink/af_netlink.c:1328
  netlink_sendmsg+0x8a5/0xd60 /net/netlink/af_netlink.c:1917
  sock_sendmsg_nosec /net/socket.c:633 [inline]
  sock_sendmsg+0xd7/0x130 /net/socket.c:653
  ___sys_sendmsg+0x803/0x920 /net/socket.c:2307
  __sys_sendmsg+0x105/0x1d0 /net/socket.c:2352
  __do_sys_sendmsg /net/socket.c:2361 [inline]
  __se_sys_sendmsg /net/socket.c:2359 [inline]
  __x64_sys_sendmsg+0x78/0xb0 /net/socket.c:2359
  do_syscall_64+0xfd/0x6a0 /arch/x86/entry/common.c:296
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4401d9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7  
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff767975d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401d9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a60
R13: 0000000000401af0 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 6937a8efb11262f5 ]---
RIP: 0010:nla_parse_nested_deprecated /./include/net/netlink.h:1167 [inline]
RIP: 0010:tcf_ife_init+0x25c/0x1850 /net/sched/act_ife.c:484
Code: 00 00 48 c7 c7 40 c2 da 88 e8 f0 8c a2 fb 48 89 da 48 b8 00 00 00 00  
00 fc ff df 48 c7 85 e8 fe ff ff 00 00 00 00 48 c1 ea 03 <0f> b6 14 02 48  
89 d8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 e2
RSP: 0018:ffff88809032eeb8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff110119c21b0
RDX: 0000000000000000 RSI: 1ffff110119c21b7 RDI: 0000000000000282
RBP: ffff88809032f060 R08: 0000000000000002 R09: ffff88808ce10d88
R10: fffffbfff134a0cf R11: ffffffff89a5067f R12: 0000000000000001
R13: ffff8882166dd240 R14: ffff88809032f8c0 R15: 0000000000000000
FS:  0000555556e20880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000180 CR3: 0000000088374000 CR4: 00000000001406f0


---
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